With quickly increased population of the world and the fact that there is only limited land available for use by human being, cremation has become an inevitable trend in many countries. A coffin for use in the cremation must be made of combustible material, such as wood and paper. The use of large quantity of wood material would have adverse influence on the protection of environment and natural resource. Therefore, it seems improper to make coffins with wood. Moreover, since the coffin is burnt to ashes along with the corpse carried by it, it would be more practical and economical to use paper coffin. Paper coffins used in early stage are made by folding corrugated paperboards into a desired shape. Such corrugated paperboard coffin has only limited structural strength and is therefore not reliable for use. Thereafter, there is other paper coffin developed by assembling paper panels together. To strengthen the paper panels, supporting walls are provided between inner and outer layers of each paper panel. The supporting walls may include perpendicularly intersected studs or honeycomb structure that would increase the cost of manufacturing the paper coffin.